The present invention relates to apparatus for controlling the liquid level in tanks and, in particular, to such apparatus for use in toilet flush tanks.
Various types of valves have utilized a flexible, resilient pinch tube as the valve member, which is controlled by a lever-type actuator engageable with the outside of the tube to pinch it closed. Such a valve is disclosed, for example, in U.S. Pat. No. 5,402,823. Pinch tube valves have heretofore been used as toilet level control valves, for example in U.S. Pat. No. 3,996,960. However, such valves have typically utilized a ball cock mechanism wherein the actuator is coupled by a long arm to a float. Such ball cock devices require considerable lateral space in the tank to accommodate the float and its arm.
It is also known to utilize flush tank level control valves with floats which encircle and ride up and down along an upright fill tube, so as to occupy less space in the tank. Such valves have heretofore utilized a poppet-type valve mechanism, which is of relatively complex construction.